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Article
Publication date: 27 July 2021

Mervin Ealiyas Mathews, Anand N, Diana Andrushia A, Tattukolla Kiran and Khalifa Al-Jabri

Building elements that are damaged by fire are often strengthened by fiber wrapping techniques. Self-compacting concrete (SCC) is an advanced building material that is…

Abstract

Purpose

Building elements that are damaged by fire are often strengthened by fiber wrapping techniques. Self-compacting concrete (SCC) is an advanced building material that is widely used in construction due to its ability to flow and pass through congested reinforcement and fill the required areas easily without compaction. The aim of the research work is to examine the flexural behavior of SCC subjected to elevated temperature. This research work examines the effect of natural air cooling (AC) and water cooling (WC) on flexural behavior of M20, M30, M40 and M50 grade fire-affected retro-fitted SCC. The results of the investigation will enable the designers to choose the appropriate repair technique for improving the service life of structures.

Design/methodology/approach

In this study, an attempt has been made to evaluate the flexural behavior of fire exposed reinforced SCC beams retrofitted with laminates of carbon fiber reinforced polymer (CFRP), basalt fiber reinforced polymer (BFRP) and glass fiber reinforced polymer (GFRP). Beam specimens were cast with M20, M30, M40 and M50 grades of SCC and heated to 925ºC using an electrical furnace for 60 min duration following ISO 834 standard fire curve. The heated SCC beams were cooled by either natural air or water spraying.

Findings

The reduction in the ultimate load carrying capacity of heated beams was about 42% and 55% for M50 grade specimens that were cooled by air and water, respectively, in comparison with the reference specimens. The increase in the ultimate load was 54%, 38% and 27% for the specimens retrofitted with CFRP, BFRP and GFRP, respectively, compared with the fire-affected specimens cooled by natural air. Water-cooled specimens had shown higher level of damage than the air-cooled specimens. The specimens wrapped with carbon fiber could able to improve the flexural strength than basalt and glass fiber wrapping.

Originality/value

SCC, being a high performance concrete, is essential to evaluate the performance under fire conditions. This research work provides the flexural behavior and physical characteristics of SCC subjected to elevated temperature as per ISO rate of heating. In addition attempt has been made to enhance the flexural strength of fire-exposed SCC with wrapping using different fibers. The experimental data will enable the engineers to choose the appropriate material for retrofitting.

Details

Journal of Structural Fire Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 20 February 2020

Daniel Paul Thanaraj, Anand N. and Prince Arulraj

The purpose of this study is to investigate the effect of standard fire on the strength and microstructure properties of concrete with different strength grades.

Abstract

Purpose

The purpose of this study is to investigate the effect of standard fire on the strength and microstructure properties of concrete with different strength grades.

Design/methodology/approach

Different strength grades of concrete used for the investigation are M20, M30, M40 and M50. An electrical bogie hearth furnace was developed to simulate the International Standards Organization 834 standard fire curve.Concrete samples were subjected to high temperatures of 925, 1,029, 1,090 and 1,133°C for the duration of 1, 2, 3 and 4 h, respectively, as per standard fire curve. Compressive strength, tensile strength, thermal crack pattern and spalling of heated concrete specimens were evaluated by experimental investigation. Scanning electron microscopy and thermo-gravimetric analysis were performed to investigate the microstructure properties of heated concrete specimens.

Findings

Test results indicated reduction in the strength and changes in the microstructure properties of concrete exposed to elevated temperature. The degree of weight and the strength loss were found to be higher for concrete with higher grades. An empirical relation is proposed to determine the residual strength of concrete with different strength grade using regression analysis.

Social implications

Results of this research will be useful for the design engineers to understand the behavior of concrete exposed to elevated temperature as per standard fire.

Originality/value

When concrete is exposed to elevated temperature, its internal microstructure changes, thereby strength and durability of concrete deteriorates. The performance of concrete with different strength grade exposed to standard fire is well understood. This research’s findings will be useful for the designers to understand more about fire resistance of concrete. A simple relationship is proposed to determine the residual strength of concrete exposed to various durations of heating.

Details

Journal of Structural Fire Engineering, vol. 11 no. 3
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 9 December 2020

Parthasarathi N. and Satyanarayanan K.S.

Technological innovations in the construction field correspond to a wider revolution in metropolitan life and in structural design. With the demand for advanced concrete…

Abstract

Purpose

Technological innovations in the construction field correspond to a wider revolution in metropolitan life and in structural design. With the demand for advanced concrete technology, the introduction of new reinforced materials in concrete, namely, iron, steel and other reinforcing elements. Reinforcement in concrete is developed in the centuries back and several advancements are being stirred to improvise the properties of the concrete through reinforcements. On the basis of this finding from the earlier research studies, a reinforcement methodology is practiced on the current study to investigate the deflection of the M30 mix concrete frame under thermal load conditions.

Design/methodology/approach

For the examination, corner and the middle frame are considered with the reinforcement provided on four zones with 16-mm diameter for compression and 8-mm diameter is used for the stirrup at 150 mm c/c spacing. The load is applied to the column with live and wall load of 3.5 kN/m and 14.7KN/m. The experimentation is carried out by the finite element analysis strategy in ABAQUS simulation software with five test conditions with the bare frame at single, two and three-bay infill. The model of the frame is developed and meshed with the meshing type of C3D8T under 8-node thermally coupled brick mesh type for the mesh size of 25 mm.

Findings

From the simulation outcome, the effect of thermal gradient on the reinforced concrete is analyzed and its structural properties are plotted as performance graphs in the result section.

Originality/value

Under the thermal load condition, the model is simulated for 180 min for five different cases and analyzed the deflection parameters such as deformation, stress and failure rate.

Details

Journal of Structural Fire Engineering, vol. 12 no. 1
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 18 June 2021

Adithya Tantri, Gopinatha Nayak, Adithya Shenoy and Kiran K. Shetty

This study aims to present the results of an experimental evaluation of low (M30), mid (M40) and high (M50) grade self-compacting concrete (SCC) with three nominal maximum…

Abstract

Purpose

This study aims to present the results of an experimental evaluation of low (M30), mid (M40) and high (M50) grade self-compacting concrete (SCC) with three nominal maximum aggregate sizes (NMAS), namely, 20 mm, 16 mm and 12.5 mm, with Bailey gradation (BG) in comparison with Indian standard gradation (ISG).

Design/methodology/approach

This study was conducted in a laboratory by testing the characteristics of fresh and hardened properties of self-compacting concrete.

Findings

Rheological and mechanical properties of SCC were evaluated in detail and according to the results, a concrete sample containing lower NMAS with BG demonstrated improvement in modulus of elasticity and compressive strength, while improving the rheological properties as well. Meanwhile, SCC demonstrated poor performance in split tensile and flexural strengths with lower NMAS gradations and a direct correlation was evident as the increase in NMAS caused an increase in the strength and vice-versa.

Originality/value

Upon comparison of BG with ISG, it was revealed that BG mixes succeeded to demonstrate superior performance. From the material optimization, rheological and mechanical performance study, it is recommended that BG with NMAS 16 mm can be used for conventional SCC.

Details

Journal of Engineering, Design and Technology , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1726-0531

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Article
Publication date: 5 February 2021

Alwyn Varghese, Anand N., Diana Andrushia and Prince Arulraj

Aim of this research work is to examine the stress–strain behavior and modulus of elasticity of fiber-reinforced concrete (FRC) exposed to elevated temperature. The…

Abstract

Purpose

Aim of this research work is to examine the stress–strain behavior and modulus of elasticity of fiber-reinforced concrete (FRC) exposed to elevated temperature. The purpose of this paper is to study the effect of standard fire exposure on the mechanical and microstructure characteristics of concrete specimens with different strength grade.

Design/methodology/approach

An electrical bogie hearth furnace was developed to simulate the ISO 834 standard fire curve. Specimens were exposed to high temperatures of 821°C, 925°C and 986°C for the duration of 30, 60 and 90 min, respectively, as per standard fire curve. Peak stress, peak strain, modulus of elasticity and damage level of heated concrete specimens were evaluated by experimental investigation. SEM-based microstructure investigation has been carried out to analyze the microstructure characteristics of heated concrete specimens.

Findings

The results revealed that carbon fiber reinforced concrete was found to be better than the FRC made with other fibers on improving the modulus of elasticity of concrete. An empirical relationship has been established to predict the modulus of elasticity of temperature exposed specimens with different type of fiber and grade of concrete. In comparison with low melting point fibers, high melting point fibers exhibited higher modulus of elasticity under all tested conditions. Surface damage and porosity level of concrete with carbon and basalt fibers were found to be lower than other FRC.

Originality/value

Empirical relationship was developed to determine the modulus of elasticity of concrete exposed to elevate temperature, and this will be useful for concrete design applications. This research work may be useful for finding the residual compressive strength of concrete exposed to elevate temperature. So that it will be helpful to identify the suitable repair/retrofitting technique for reinforced concrete elements.

Details

World Journal of Engineering, vol. 18 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

Abstract

Details

Pigment & Resin Technology, vol. 41 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 15 June 2011

Amrutha, Gopinatha Nayak, Mattur Narasimhan and S. Rajeeva

Quite often, concrete in structures is likely to get exposed to high temperatures, including an incident of fire. The strength-retention properties of concrete after such…

Abstract

Quite often, concrete in structures is likely to get exposed to high temperatures, including an incident of fire. The strength-retention properties of concrete after such an exposure are of great importance in terms of the serviceability of buildings. This paper presents an experimental study on the strength retention and impermeability aspects of a set of self compacting, high-volume fly ash concrete mixes under elevated temperatures. Five selfcompacting concrete mixes with a higher 60% level of cement replacement with fly-ash, are designed and the effects of elevated temperatures, in the range of 200-800°C, on the physical, mechanical and durability properties of these mixes are assessed. The assessment is in terms of the weight losses and the reduction in the compressive strengths of concrete cubes and split tensile strengths of concrete cylinders. The durability characteristics are assessed in terms of RCPT test results on these mixes. Performances of these self compacting concrete mixes (SCC) at elevated temperatures are also compared with two normally-vibrated concrete mixes (NCs) of an equivalent M30 strength grade. Test results indicate that weight of the specimens significantly get reduced with an increase in the level of elevated temperature, with sharp variations beyond 600°C. The experimental results also show that large improvements against chloride-ion penetration and better strength-retention at higher temperatures can be realized with self-compacting high-volume fly-ash concrete mixes additionally admixed with GGBFS and silica fume.

Details

Journal of Structural Fire Engineering, vol. 2 no. 2
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 1 September 1982

One of the more recent additions to the range of additives from Diamond Shamrock UK Ltd., P.O. Box 1, Silk Street, Eccles, Manchester M30 OBH, are their Photomer…

Abstract

One of the more recent additions to the range of additives from Diamond Shamrock UK Ltd., P.O. Box 1, Silk Street, Eccles, Manchester M30 OBH, are their Photomer speciality polyfunctional monomers and photocurable oligomers for use in the production of radiation curable inks and coatings.

Details

Pigment & Resin Technology, vol. 11 no. 9
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 10 September 2018

Yoo Jin Kwon and Kyoung-Nan Kwon

The purpose of this study is to understand the values consumers pursue and roles consumers partake in selfie practice.

Abstract

Purpose

The purpose of this study is to understand the values consumers pursue and roles consumers partake in selfie practice.

Design/methodology/approach

A qualitative research method was adopted. In-depth interviews were conducted with selfie enthusiasts. Data were analyzed with grounded theory approach.

Findings

Diverse activities and reflections pertaining to selfies were analyzed, which uncovered three consumer roles departmentalized and the nine values that selfie practice generates for consumers. The three roles are subject, photographer and user of selfies, and the roles are orchestrated together or selectively performed if necessary. In consequence of the interplay of performances and expectations of the roles, consumers pursue and gain four collaboratively created values and five individually created values.

Originality/value

Findings of the study expand the understanding of values of selfie practice and consumer roles in Web 2.0.

Details

Qualitative Market Research: An International Journal, vol. 21 no. 4
Type: Research Article
ISSN: 1352-2752

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Article
Publication date: 1 December 1985

Peter Wild

Fillworth Ltd and Millroom Accessories & Chemicals Ltd have within their range of equipment three machines which probably represent the first major development in mixing…

Abstract

Fillworth Ltd and Millroom Accessories & Chemicals Ltd have within their range of equipment three machines which probably represent the first major development in mixing technology for many years.

Details

Pigment & Resin Technology, vol. 14 no. 12
Type: Research Article
ISSN: 0369-9420

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